Ridgecrest climate

Ridgecrest Frost Dates and Growing Season

NOAA 1991-2020 normals for China Lake Naf, 7.4 km from Ridgecrest, elevation 2230 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for China Lake Naf. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around March 11 and the first fall freeze around November 12, a growing season of about 244 days.

Median at 36°F
last April 3, first November 2
Median at 32°F
last March 11, first November 12
Median at 28°F
last February 20, first November 23

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FApr 22Apr 15Apr 10Apr 7Apr 3Mar 30Mar 25Mar 18Mar 11
32°FApr 9Apr 2Mar 24Mar 17Mar 11Mar 6Mar 2Feb 26Feb 18
28°FMar 9Mar 3Feb 28Feb 25Feb 20Feb 15Feb 10Feb 4Jan 29
24°FFeb 25Feb 16Feb 10Feb 5Jan 31Jan 27Jan 21Jan 14Jan 2
20°FFeb 6Jan 30Jan 21Jan 15Jan 9Jan 4Dec 31Dec 26Dec 15
16°FJan 22Jan 13Jan 8Jan 3Jan 1Dec 30Dec 25Dec 19Dec 11

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 21Oct 25Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 15
32°FOct 29Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25
28°FNov 6Nov 13Nov 17Nov 20Nov 23Nov 26Nov 29Dec 2Dec 6
24°FNov 19Nov 24Nov 28Dec 1Dec 4Dec 7Dec 10Dec 15Dec 26
20°FNov 28Dec 3Dec 7Dec 10Dec 15Dec 20Dec 27Jan 1Jan 10
16°FDec 6Dec 11Dec 15Dec 21Dec 27Dec 30Jan 1Jan 5Jan 14

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F239231225219214209204198190
32°F269259254248244238231224213
28°F302293286280275270264257249
24°F340329322315308301294287276
20°F365362353346341336330321309
16°F365365365365365363356348339

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
85% of years
16°F or colder
40% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
2,491
Cooling degree days, base 65°F
2,620
Growing degree days, base 40°F
9,295
Growing degree days, base 45°F
7,597
Growing degree days, base 50°F
6,075
Growing degree days, base 55°F
4,753
Growing degree days, base 60°F
3,600

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January606021
February420071
March2607227
April11557394
May25238677
June1484933
July06971,162
August06491,114
September4390835
October7795485
November3592136
December623018

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 7.4 km from Ridgecrest. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00093104 (China Lake Naf). Public domain.